Biotic stress
- Biotic stress refers
to damage to crops by living organisms, such as bacteria, viruses, fungi,
parasites, harmful insects, weeds, and cultivated or native plants. The
changing climate and occurrence of extreme weather events caused a shift in
biotic stress. Climate change is one of the major factors for spreading insect-pests
and diseases.
- The losses in
yield due to lack of plant-protection measures vary from 46 to 96% depending on
the crop and varieties.
- Appropriate plant protection measures are not taken up by the farmers to check the diseases like leaf blast, neck blast, and finger blast; and insect pests like stem borer, aphid, and the grasshopper in finger millet and shoot fly incidence in little millet. Delayed onset of monsoon leading to late sowing of pulses in dryland areas also increases the incidence of pests, especially pod-borer in chickpea.
Incidence of the sterility mosaic virus in pigeon pea plants when they are less than 45 days old, results in 95–100% yield losses, while older plants suffer only 26–97% loss. Growing tolerant cultivars will reduce the best option to overcome the problem of insect pests and disease.